Monday, December 12, 2011


From: "Michael E. Mann" <>
To: Phil Jones <>, Keith Briffa <>, Tim Osborn <>,,,,
Subject: Re:
Date: Thu, 02 Oct 2003 17:03:15 -0400

For those of you who haven't seen it, this is Robert Matthews last article on the topic.
Hence the fairly brusque tone taken...
Middle Ages were warmer than today, say scientists

By Robert Matthews, Science Correspondent
(Filed: 06/04/2003)

Claims that man-made pollution is causing "unprecedented"
global warming
have been seriously undermined by new research which shows that the
was warmer during the Middle Ages.

From the outset of the global warming debate in the late 1980s,
environmentalists have said that temperatures are rising higher and
than ever before, leading some scientists to conclude that greenhouse
from cars and power stations are causing these
"record-breaking" global

Last year, scientists working for the UK Climate Impacts Programme said
global temperatures were "the hottest since records began"
and added: "We
are pretty sure that climate change due to human activity is here and

This announcement followed research published in 1998, when scientists
the Climatic Research Unit at the University of East Anglia declared
the 1990s had been hotter than any other period for 1,000 years.

Such claims have now been sharply contradicted by the most
study yet of global temperature over the past 1,000 years. A review of
than 240 scientific studies has shown that today's temperatures
are neither
the warmest over the past millennium, nor are they producing the most
extreme weather - in stark contrast to the claims of the

The review, carried out by a team from Harvard University, examined the
findings of studies of so-called "temperature proxies" such as
tree rings,
ice cores and historical accounts which allow scientists to estimate
temperatures prevailing at sites around the world.

The findings prove that the world experienced a Medieval Warm Period
the ninth and 14th centuries with global temperatures significantly
even than today.

They also confirm claims that a Little Ice Age set in around 1300,
which the world cooled dramatically. Since 1900, the world has begun to
up again - but has still to reach the balmy temperatures of the Middle

The timing of the end of the Little Ice Age is especially significant, as
implies that the records used by climate scientists date from a time
the Earth was relatively cold, thereby exaggerating the significance of
today's temperature rise.

According to the researchers, the evidence confirms suspicions that
"unprecedented" temperatures are simply the result of
examining temperature
change over too short a period of time.

The study, about to be published in the journal Energy and Environment,
been welcomed by sceptics of global warming, who say it puts the claims
environmentalists in proper context. Until now, suggestions that the
Ages were as warm as the 21st century had been largely anecdotal and
often challenged by believers in man-made global warming.

Dr Philip Stott, the professor emeritus of bio-geography at the
of London, told The Telegraph: "What has been forgotten in all the
discussion about global warming is a proper sense of history."

According to Prof Stott, the evidence also undermines doom-laden
about the effect of higher global temperatures. "During the Medieval
Period, the world was warmer even than today, and history shows
that it was
a wonderful period of plenty for everyone."

In contrast, said Prof Stott, severe famines and economic collapse
the onset of the Little Ice Age around 1300. He said: "When the
started to drop, harvests failed and England's vine industry died. It
one wonder why there is so much fear of warmth."

The United Nation's Intergovernmental Panel on Climate Change (IPCC),
official voice of global warming research, has conceded the possibility
today's "record-breaking" temperatures may be at least
partly caused by the
Earth recovering from a relatively cold period in recent history. While
evidence for entirely natural changes in the Earth's temperature
to grow, its causes still remain mysterious.

Dr Simon Brown, the climate extremes research manager at the
Office at Bracknell, said that the present consensus among scientists on
IPCC was that the Medieval Warm Period could not be used to judge the
significance of existing warming.

Dr Brown said: "The conclusion that 20th century warming is not
relies on the assertion that the Medieval Warm Period was a global
phenomenon. This is not the conclusion of IPCC."

He added that there were also doubts about the reliability of
proxies such as tree rings: "They are not able to capture the recent
of the last 50 years," he said.

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At 04:11 PM 10/2/2003 -0400, Michael E. Mann wrote:

Dear Mr. Matthews,
Unfortunately Phil Jones is travelling and will probably be unable to offer a separate
reply. Since your comments involve work that is his as well, I have therefore taken the
liberty of copying your inquiry and this reply to several of his British colleagues.
The comparisons made in our paper are well explained therein, and your statements belie
the clearly-stated qualifications in our conclusions with regard to separate analyses of
the Northern Hemisphere, Southern Hemisphere, and globe.
An objective reading of our manuscript would readily reveal that the comments you refer
to are scurrilous. These comments have not been made by scientists in the peer-reviewed
literature, but rather, on a website that, according to published accounts, is run by
individuals sponsored by ExxonMobile corportation, hardly an objective source of
Owing to pressures on my time, I will not be able to respond to any further inquiries
from you. Given your extremely poor past record of reporting on climate change issues,
however, I will leave you with some final words. Professional journalists I am used to
dealing with do not rely upon un-peer-reviewed claims off internet sites for their
sources of information. They rely instead on peer-reviewed scientific research, and
mainstream, rather than fringe, scientific opinion.
Michael E. Mann
At 08:30 PM 10/2/2003 +0100, Robert Matthews wrote:

Dear Professor Mann

I'm putting together a piece on global warming, and I'll be making reference to your
paper in Geophysical Research Letters
with Prof Jones on "Global surface temperatures over the past two millennia".

When the paper came out, some critics argued that the paper actually showed that there
have been three periods in the last 2000 years which were warmer than today (one just
prior to AD 700, one just after, and one just prior to AD 1000). They also claimed that
the paper could only conclude that current temperatures were warmer if one compared the
proxy data with other data sets. (For an example of these arguments, see:

I'd be very interested to include your rebuttals to these arguments in the piece I'm
doing. I must admit to being confused by why proxy data should be compared to
instrumental data for the last part of the data-set. Shouldn't the comparison be a
consistent one throughout ?

With many thanks for your patience with this
Robert Matthews
Robert Matthews
Science Correspondent, The Sunday Telegraph
C/o: 47 Victoria Road, Oxford, OX2 7QF
Email: [2]
Homepage: [3]
Tel: (+44)(0)1865 514 004 / Mob: 0790-651 9126

Professor Michael E. Mann
Department of Environmental Sciences, Clark Hall
University of Virginia
Charlottesville, VA 22903
e-mail: Phone: (434) 924-7770 FAX: (434) 982-2137

Professor Michael E. Mann
Department of Environmental Sciences, Clark Hall
University of Virginia
Charlottesville, VA 22903
e-mail: Phone: (434) 924-7770 FAX: (434) 982-2137



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